We just upgraded to 04 in my place of employment. The first thing I noticed in large assembly was the jerkiness. If I load parts lightweight, it is terrible when I rotate. If I resolve the parts, it rotates better. But the zoom in and out is unbearable to us. There is a lag and the cursor sits there for a second. Then it zooms in or out. We have tried every combination of settings we could find and it is still crappy. 2003 ran flawless with the same settings, PCs, video cards, ect. I brought the disks home and loaded onto 2 home machines for an experiment. Generally my home PCs run much better than the ones in work. Im still having the same problem. I was under the impression that 04 was going to be "better". Im pretty disgusted at the moment. Any ideas of a setting I might be missing. When I say "large assembly" I am only working with maybe 500 parts tops :) Thanks, Jake Barron